From patchwork Mon May 16 23:04:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eugene Syromiatnikov X-Patchwork-Id: 12851647 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E887CC433F5 for ; Mon, 16 May 2022 23:05:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350054AbiEPXFJ (ORCPT ); Mon, 16 May 2022 19:05:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350018AbiEPXFJ (ORCPT ); Mon, 16 May 2022 19:05:09 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A59B045525 for ; Mon, 16 May 2022 16:05:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652742306; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type; bh=XWqMzw1NbrOQqMg0//tnmzedML/So/AECv/iAu4oGTQ=; b=YcyFr5zdXvAbmrRawTwtXIU+3HX2MZgCPPuK6nzsQbfiwM1bC74guA+If6Oc1Lk6lAPm8y ohj3rXzm2boviknKiAUlX7FKQH4Z0ihEzrN9jDtVs78wpOBrEo9mPzUScN3y28bYquxxZR vg1pyLsdGBTf8Ffv18vJRzcsCGNBm/c= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-417-xoS2vbd9O0aNGqsh54rUhg-1; Mon, 16 May 2022 19:05:03 -0400 X-MC-Unique: xoS2vbd9O0aNGqsh54rUhg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A0ED9185A7BA; Mon, 16 May 2022 23:05:02 +0000 (UTC) Received: from asgard.redhat.com (unknown [10.36.110.3]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 53B44568626; Mon, 16 May 2022 23:04:58 +0000 (UTC) Date: Tue, 17 May 2022 01:04:55 +0200 From: Eugene Syromiatnikov To: Jiri Olsa , Masami Hiramatsu , Steven Rostedt , Ingo Molnar , Alexei Starovoitov , Daniel Borkmann Cc: Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Shuah Khan , linux-kselftest@vger.kernel.org Subject: [PATCH bpf v2 1/4] bpf_trace: check size for overflow in bpf_kprobe_multi_link_attach Message-ID: <20220516230455.GA25103@asgard.redhat.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Check that size would not overflow before calculation (and return -EOVERFLOW if it will), to prevent potential out-of-bounds write with the following copy_from_user. Add the same check to kprobe_multi_resolve_syms in case it will be called from elsewhere in the future. Fixes: 0dcac272540613d4 ("bpf: Add multi kprobe link") Signed-off-by: Eugene Syromiatnikov --- kernel/trace/bpf_trace.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index d8553f4..f1d4e68 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2352,12 +2352,15 @@ static int kprobe_multi_resolve_syms(const void __user *usyms, u32 cnt, unsigned long *addrs) { - unsigned long addr, size; + unsigned long addr, sym_size; + u32 size; const char __user **syms; int err = -ENOMEM; unsigned int i; char *func; + if (check_mul_overflow(cnt, (u32)sizeof(*syms), &size)) + return -EOVERFLOW; size = cnt * sizeof(*syms); syms = kvzalloc(size, GFP_KERNEL); if (!syms) @@ -2382,9 +2385,9 @@ kprobe_multi_resolve_syms(const void __user *usyms, u32 cnt, addr = kallsyms_lookup_name(func); if (!addr) goto error; - if (!kallsyms_lookup_size_offset(addr, &size, NULL)) + if (!kallsyms_lookup_size_offset(addr, &sym_size, NULL)) goto error; - addr = ftrace_location_range(addr, addr + size - 1); + addr = ftrace_location_range(addr, addr + sym_size - 1); if (!addr) goto error; addrs[i] = addr; @@ -2429,6 +2432,8 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (!cnt) return -EINVAL; + if (check_mul_overflow(cnt, (u32)sizeof(*addrs), &size)) + return -EOVERFLOW; size = cnt * sizeof(*addrs); addrs = kvmalloc(size, GFP_KERNEL); if (!addrs)